Researchers identify immune system irregularities that may cause itching

May 27, 2016 by Jim Dryden, Washington University School of Medicine in St. Louis
In a small study of patients who have chronic itching with no known cause, researchers from the Center for the Study of Itch at Washington University School of Medicine in St. Louis identified immune system irregularities that may prompt the urge to scratch.

People who suffer itching with no clear cause may have previously unrecognized immune system defects. In a small study of such patients, researchers from the Center for the Study of Itch at Washington University School of Medicine in St. Louis identified immune system irregularities that may prompt the urge to scratch.

The findings are reported in the May issue of The Journal of the American Academy of Dermatology.

"As doctors, we throw things like antihistamines, ointments and lotions at patients who suffer chronic itching, but if there is something profoundly abnormal about the —as it appears there is—then we can't solve the itching until we address those underlying causes," said principal investigator Brian S. Kim, MD, an assistant professor of medicine in the Division of Dermatology. "The immune system needs to be in balance, and we hope to find ways to restore that balance in patients with this very debilitating condition."

The researchers took and skin biopsies from a small sample of patients—only four are reported in the study—to look for immune problems. They found "an incredible amount of dysfunction," Kim said, adding that he has seen similar defects in numerous additional patients not included in the current study.

The four patients researchers zeroed in on were ages 75 to 90. In blood samples, three of those four had high levels of the protein IgE—an immunoglobulin that is a marker of inflammation. Immunoglobulins are antibodies deployed by the immune system to fight infections. Elevated levels of IgE often are seen in patients with allergies.

The researchers also noted very low levels of an immunoglobulin known as IgG; abnormally low counts of a type of immune cell called a CD8 T-cell; and an elevated number of called eosinophils, which are markers of allergic inflammation.

"Curiously, none of these patients had any history of allergic disorders," Kim said. "We often see similarly high counts of eosinophils in patients with eczema, but the patients we studied didn't have eczema. They didn't even have a rash. Only itching."

Kim explained that dermatologists frequently take skin biopsies when a patient has a rash, but with chronic itching of unknown origin, which doctors call chronic idiopathic pruritis, there is nothing evident to biopsy.

The study's first author, Amy Xu, a medical student in Kim's lab, said most patients with this type of unexplained, chronic itching tend to be older and develop itching problems later in life.

"It may be caused by some sort of wear and tear on the immune system," Xu said.

Because of the small number of patients in the study, it's too soon to draw firm conclusions, but the itching may be an indication that something else in the body is going wrong, Kim said.

"We have begun working on a mouse model in which the animals have similar defects," he said. "We want to learn whether these changes in the immune system create only itching or whether they could be signs that some other problem is present."

Explore further: Skin care tips for psoriasis patients

More information: Amy Z. Xu et al. Immune dysregulation underlies a subset of patients with chronic idiopathic pruritus, Journal of the American Academy of Dermatology (2016). DOI: 10.1016/j.jaad.2015.11.029

Related Stories

Skin care tips for psoriasis patients

August 25, 2013
(HealthDay)—Sun protection is among the skin care habits that can help people with the chronic skin condition psoriasis reduce some of the discomfort they may experience, such as skin itching, cracking and bleeding, an ...

Scientists unravel mechanisms in chronic itching

October 15, 2013
Anyone who has suffered through sleepless nights due to uncontrollable itching knows that not all itching is the same. New research at Washington University School of Medicine in St. Louis explains why.

New study finds similarities in blood cytokine levels across three major psychiatric disorders

March 29, 2016
Emory researchers recently released a study comparing blood cytokine levels in patients with schizophrenia, bipolar disorder and major depressive disorder. Cytokines are key signaling molecules of the immune system. The study ...

Bacterial infections suppress protective immune response in neurodermatitis

November 19, 2014
The skin condition neurodermatitis affects nearly one in four children and also occurs frequently in adults. Many patients also develop infections in the dry, open patches of skin, for example due to colonization by the pathogenic ...

Fighting cancer with the help of someone else's immune cells

May 19, 2016
A new step in cancer immunotherapy: researchers from the Netherlands Cancer Institute and University of Oslo/Oslo University Hospital show that even if one's own immune cells cannot recognize and fight their tumors, someone ...

Itching for new help for eczema: Recently identified immune cells possible therapeutic target

January 30, 2013
Researchers have identified a previously unknown critical role for a recently identified immune cell population in the progression of atopic dermatitis. The team found an accumulation of innate lymphoid cells in the active ...

Recommended for you

Animal study shows how to retrain the immune system to ease food allergies

February 21, 2018
Treating food allergies might be a simple matter of teaching the immune system a new trick, researchers at Duke Health have found.

'Icebreaker' protein opens genome for T cell development, researchers find

February 20, 2018
Almost all cells in the human body have identical DNA sequences, yet there are 200-plus cell types with different sizes, shapes, and chemical compositions. Determining what parts of the genome are read to make protein and ...

Preventive treatment for peanut allergies succeeds in study

February 20, 2018
The first treatment to help prevent serious allergic reactions to peanuts may be on the way. A company said Tuesday that its daily capsules of peanut powder helped children build tolerance in a major study.

Infection site affects how a virus spreads through the body

February 20, 2018
A person is more likely to get infected by HIV through anal intercourse than vaginal, but no one knows quite why. A new study by scientists at the Gladstone Institutes shows that infection sites could affect the immune system's ...

Unexpected immune activation illustrated in the cold

February 19, 2018
Researchers at Utrecht University and Leiden University Medical Center, the Netherlands, have imaged an important immune system on-switch. Their novel technical approach has led to the discovery of two ways in which the immune ...

Immune signature predicts asthma susceptibility

February 16, 2018
Asthma is a chronic inflammatory disease driven by the interplay of genetics, environmental factors and a diverse cast of immune cells. In their latest study, researchers at La Jolla Institute for Allergy and Immunology (LJI) ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.